TIM CLUT Question

Graphic based area of development (Graphics Processing Unit), including the Geometry Transform Engine (GTE), TIM, STR (MDEC), etc.
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Kneesnap
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TIM CLUT Question

Post by Kneesnap » September 1st, 2018, 12:39 pm

I am creating a modding tool for a PSX / PC game, and the PSX image format appears similar to the TIM file format.

I'm reading from this to try and understand how this works, but it seems to leave a key bit of information out.

Specifically,
Image


After reading the index values listed, how are those indexes related to the CLUT? How do I get a color from the CLUT from those numbers?

Kneesnap
Interested PSXDEV User
Interested PSXDEV User
Posts: 6
Joined: September 22nd, 2017, 6:29 am

Re: TIM CLUT Question

Post by Kneesnap » September 1st, 2018, 8:01 pm

Alright, after a while I figured out several things.

1. I was not reading CLUTs properly.
2. It's just a 4-bit index (0-15), which can be grabbed easily from the CLUT.

However, this raises a new final problem:

I can't seem to figure out a way to determine which CLUT to use. There are around 150 CLUT tables just in this one file I'm testing with. If I hard-code the CLUT ID, it works perfectly, so I know I've gotten everything up until this point working.

The only data I seem to have is a "clut_id" short value, which appears to be generated by taking the x, y clut coordinates and turning it into a single number. It appears to be part of LIBGPU.H:

Code: Select all

#define getClut(x, y) 	(((y)<<6)|(((x)>>4)&0x3f))
However, either I am reversing this wrong, or this isn't going to help me figure out which CLUT to use.

I feel like it would probably be best at this point to try asking what others think, as the answer is probably right in front of me, I just don't see it.

Here are some things which may help me:

1. Please come up with some statements to take a number generated by the above getClut function, so I can confirm it's not just me doing the math wrong.

2. Given the structs below, what might be used to identify which CLUT to use?

Code: Select all

struct {
	RECT			ts_vram_rect;   // See below for struct. Holds Vram coordinates, and full image dimensions.
	MR_ULONG		ts_vram_offset; // Misleading name. This is just a pointer to where the image data is.
	MR_USHORT		ts_id;           // Texture ID.
	MR_USHORT		ts_tpage_id; // Texture Page ID.
	MR_USHORT		ts_clut_id;   // This is the value I mention above, presumed to be generated by getClut.
	MR_USHORT		ts_flags;      // Texture flags. Nothing much to see here.
	MR_UBYTE		ts_u;  // Used to create texture UVs
	MR_UBYTE		ts_v; //
	MR_UBYTE		ts_w; // In-game texture width. Some images have extra parts which get cut-off in-game. The full texture width is in vram_rect.
	MR_UBYTE		ts_h;  // In-game texture height. 
}; // "TXSETUP"

struct {
	short x; // Vram X
	short y; // Vram Y
	short w; // Width
	short h; // Height
}; // "RECT" This is the RECT struct from LIBGPU.H
3. Anyone with more experience that me that has any further insight than what I may have, feel free to share any tips or suggestions which might help out.

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